The invention relates to an electric iron comprising a housing, a sole plate, a first reservoir having an outlet for a first fluid, an exchangeable reservoir having an outlet for a second fluid, which has a viscosity, a nozzle means comprising at least one aperture and a pump for delivering a mixture of the first and second fluids to the nozzle means.
Such an electric iron is known from WO 99/27176. With this iron it is possible to spray an additive fluid on the fabric before it is ironed. Additive fluids can be used e.g. for achieving a starching effect or wrinkling resistance, or for making cloth hydrophylic or hydrophobic. The additive fluid is contained in the exchangeable reservoir, whereas the first reservoir contains water. By starting the pump, water as well as additive fluid is sucked from the respective reservoirs via supply tubes, whereby the additive fluid is diluted with water, after which the mixture of fluids (diluted additive fluid) is pumped to the spraying nozzle. Parts of both supply tubes are shaped as capillary tubes in order to create an underpressure at the inlets of the pump. These capillary tubes have flow resistances which limit the maximum flowrate. To control the flowrate of the additive fluid to the pump, the supply tube for the additive fluid is provided with an adjustable valve. This means that it is up to the user himself to control the proportion of the fluids, and thus the degree of dilution. This could induce mistakes and could even be rather risky, because there is a reasonable chance that the user will use a wrong adjustment, e.g. a too high concentration of the additive fluid causing damage to the cloth. This risk is even greater if the user decides to use a different reservoir with a different additive fluid. A different fluid will usually have a different viscosity. This means that it is left to the user""s competence how great the degree of dilution should be chosen. All this may lead to mistakes.
The object of the invention is to provide an electric iron in which exchangeable reservoirs containing additive fluids, possibly of different viscosity and in a concentrated form, can be used without the risk of the above problems arising.
According to the invention, the electric iron comprises a housing, a sole plate, a first reservoir having an outlet for a first fluid, an exchangeable reservoir having an outlet for a second fluid, which has a viscosity, and having coupling means, a nozzle means comprising at least one aperture, a pump for delivering a mixture of the first and second fluids to the nozzle means, said coupling means comprising a first and a second inlet and an outlet, said second inlet of the coupling being fixedly connected to the outlet of the exchangeable reservoir, the first inlet of the coupling and the outlet of the coupling being connected to the outlet of the first reservoir and to a supply tube to the pump, respectively, if the exchangeable reservoir is inserted into the iron, at least one of the inlets of the coupling and/or the outlet of the exchangeable reservoir being provided with a flow restriction which is adapted to the viscosity of the second fluid such that, given predetermined pumping characteristics of the pump, a predetermined desired flowrate of the mixture of fluids and/or a predetermined desired proportion of the first and second fluids is obtained. Every exchangeable reservoir which can be used in such an iron has its own flow restriction for the first or the second fluid or both. The flow restriction is so designed that the maximum flowrate through the inlet causes a predetermined, desired flowrate of the mixture of fluids to be delivered through the aperture of the nozzle means. It is the manufacturer of the exchangeable reservoir who determines the degree of concentration of the mixture of the fluids, not the user.
In a preferred embodiment of the iron, the second inlet of the coupling is provided with a non-return valve. This prevents liquid from flowing into or out of the exchangeable reservoir when the pump is not in operation.
In a further preferred embodiment, the outlet of the first reservoir is provided with a non-return valve. This also prevents liquid from flowing into or out of the exchangeable reservoir when the pump is not in operation. If the exchangeable reservoir is removed, it will prevent leakage.
Preferably, the exchangeable reservoir is provided with a vent and the iron is provided with a valve for opening or closing said vent. Closing the vent offers the possibility to deliver only the first fluid to the nozzle means, without the second fluid.
In a further embodiment, the outlet of the coupling is provided with a filter. The filter prevents impurities from entering the pump, which impurities could cause damage to the pump or clogging of the nozzle means.
In yet another embodiment, the aperture(s) of the nozzle means is (are) located in the sole plate.
The invention also relates to an exchangeable reservoir intended for use in the iron and having characteristics as described in the claims.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.